I have Debian 6 2.6.32-5-amd64 on netbook. With
pm-utils Sleep works but hibernate fails with error:
PM: Swap header not found!. Swap was enabled using ubuntu tutorial after installation - this is probably the key but can't find working solution.
You don't have a recognizable swap partition. Check that your swap partition is active: run
cat /proc/swaps to see what swap space is in use.
This may be a symptom of trying to hibernate to a swap file. See e.g. Ubuntu bug #313724. Some hibernation methods accept swap files, but this depends on both the hibernation method and the kernel version, and it looks like yours can't cope with a swap file. Some versions of
pm-utils can hibernate to a file; you need to configure the system to pass the proper
resume_offset argument when booting back into the hibernated system.
If you created a swap partition with a more recent operating system, or had encrypted swap before but no longer, you may need to reinitialize the swap partition. Run
mkswap on the block device corresponding to the partition (e.g.
mkswap /dev/sdz99 — make sure that you get the name and number right, since otherwise this will overwrite one of your data partitions).